Weak Lensing by Photometric Density Ridges

2026/03/04 by Mehraveh Nikjoo, Joe Zuntz, Ben Moews · 1 voice
Physics and Astronomy · #astro-ph.CO

paper · pdf

arxiv published 2026/03/04 · arxiv updated 2026/03/05

Abstract

Ridges in galaxy density fields measured by photometric surveys are 2D projections of filaments in the cosmic web, and so should lens light from background galaxies. We report on a detection of this effect in Dark Energy Survey Year 3 data at high significance, though not independently of galaxy-galaxy lensing. We describe improvements to the existing subspace-constrained mean shift algorithm to locate these ridges efficiently at scale, and examine the dependence of the signal in simulations on cosmological and algorithmic parameters. We find that it depends primarily on S₈=σ₈ ( Ω_m / 0.3 )^1/2, and discuss improvements to our methodology that would be needed to allow precision parameter estimation.

Citations

• Euclid preparation. Establishing the quality of the 2D reconstruction of the filaments of the cosmic web with DisPerSE using Euclid photometric redshifts
• Introduction to the Chinese Space Station Survey Telescope (CSST)
• Weak lensing analysis of A115, A2219 and A2261: Detection of galaxy groups and filaments around clusters
• Euclid
• SCADDA: Spatio-temporal cluster analysis with density-based distance augmentation and its application to fire carbon emissions
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package*
• KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
• The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s
• Efficient Computation of CMB anisotropies in closed FRW models

Discussions

• Paper Day! arxiv.org/abs/2603.04025 Mehraveh Nikjoo, a PhD student at the University of Gdansk, led our search for a lensing signal around ridges in foreground galaxy density fields. [bsky, 2 points, 1 comments]